Mitt Romney was subjected to furious attacks from his Republican rivals today,
as they scrambled to prevent him winning an overwhelming victory in
Tuesday's New Hampshire presidential primary.

As his poll lead here slipped, the former Massachusetts governor was accused of being a coward, a careerist and a predator capitalist in the final televised debate before the second round of voting in the party contest for a candidate to face President Barack Obama in November's presidential election.

Newt Gingrich, the former House Speaker, called on Mr Romney to stop spouting "pious baloney" about being a businessman and a political outsider who reluctantly joined the presidential race to save his country.

"Just level with the American people," Mr Gingrich told Mr Romney, who ran for the US Senate in 1994 before serving as governor, and lost a first White House bid in 2008. "You have been running since the 1990s".

Mr Gingrich also assailed Mr Romney for allowing allies to run stinging attack advertisements against him. Seconds after claiming: "I haven't seen the ads," Mr Romney said: "The ad I saw said you were forced out of the speakership".

The former Speaker pointed viewers towards newspaper articles in which the investment firm Mr Romney once ran, Bain Capital, was described as a predator that "looted" companies and laid off thousands of workers.

The assault on Mr Romney came just 10 hours after the end of another debate, 20 miles away in Manchester, in which the candidates baffled observers by failing to take on the front-runner.

This time Rick Santorum, the former Pennsylvania senator whose polling surge has fed Right-wing hopes of stopping "moderate Mitt", also lashed out at the man who beat him by just eight votes in last week's Iowa caucus.

Doubting Mr Romney would "stand up for conservative principles", Mr Santorum attacked him for boasting that his Massachusetts record would convince voters in neighbouring New Hampshire to make him the first Republican challenger ever to win both the first two states.

"If his record as Governor of Massachusetts was so great, why didn't he run for re-election?" Mr Santorum asked. "Why did you bail out?" Amid declining ratings, Mr Romney quit in 2007 after one term as governor to run for president. He was succeeded by a Democrat, who won convincingly.

Meanwhile Jon Huntsman, the US ambassador to China until last year, robustly hit back at Mr Romney for criticising him during Saturday night's debate for choosing to serve Mr Obama's administration instead of "working to elect Republicans".

"He criticised me while he was out making money," said Mr Huntsman, who enjoyed his strongest debate performance so far. "I will always put my country first".

He added: "This nation is divided because of attitudes like that."

The attempt to drag Mr Romney back down among his rivals came as a new Suffolk University poll showed he had fallen from 43 per cent of support to 35 per cent in less than a week. Ron Paul, the libertarian Texas congressman who finished third in Iowa, is sitting in second with 20 per cent.

Mr Huntsman, who has staked his entire campaign on New Hampshire after skipping Iowa, has steadily risen to third place with 11 per cent. Mr Gingrich has nine and Mr Santorum eight, according to the Suffolk poll. The figures were disappointing for Mr Santorum and suggested he had failed to convert his Iowa performance into momentum in a state less influenced by social conservatives and evangelical Christians.

Rick Perry, the governor of Texas has just one per cent of support.

While defending himself strongly throughout, Mr Romney, who has a fortune of $250 million (£164 million) risked again appearing out of touch with struggling American voters following an ill-advised offer to bet Mr Perry $10,000 in a previous debate.

He recalled his father George Romney, a millionaire governor and failed presidential candidate, telling him: "Mitt, never get involved in politics if you have to win an election to pay a mortgage." Reflecting on his 1994 Senate campaign defeat to Ted Kennedy, he added: "I was happy he had to take a mortgage out on his house to ultimately defeat me".

Eric Fehrnstrom, a senior aide to Mr Romney, told The Daily Telegraph: "It was some personal advice from a father to a son: Don't go into politics if you need the pay-cheque to pay the mortgage".